Where: Lyman County, South Dakota (43.6° N, 99.4° W: paleocoordinates 48.6° N, 67.1° W)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Baculites sp. (smooth) - Baculites perplexus ammonoid zone, Sharon Springs Member (Pierre Shale Formation), Early/Lower Campanian to Early/Lower Campanian (83.5 - 70.6 Ma)
• The Sharon Springs Member extends from Baculites sp. (smooth) - Baculites perplexus ammonite zones in South Dakota according to Gill et al. (1972) [Lower-Middle Campanian]
• bed-level stratigraphic resolution
Environment/lithology: marine; lithified, bentonitic, concretionary, black, gray shale and lithified, hematitic, black, gray shale
•thin layer of small, white, hard concretions. The upper part, known as the Upper Shale zone, has no fish fossils; and it is usually darker in color and generally contains small specks of red hematite. This zone is also somewhat less resistant to weathering than the lower one. The plesiosaur skeleton was found just a few feet above the base of the Fish Scale zone."
Size class: macrofossils
Collected by Bump, H. E. Martin in 1945
Collection methods: surface (float), surface (in situ),
Primary reference: S. P. Welles and J. D. Bump. 1949. Alzadasaurus pembertoni, a new elasmosaur from the Upper Cretaceous of South Dakota. Journal of Paleontology 23(5):521-535 [M. Carrano/H. Street]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 102092: authorized by Matthew Carrano, entered by Hallie Street on 08.01.2011
Creative Commons license: CC BY (attribution)
Taxonomic list
Reptilia | |
"Alzadasaurus pembertoni n. sp." = Styxosaurus snowii
"Alzadasaurus pembertoni n. sp." = Styxosaurus snowii Williston 1890 elasmosaur SDSM 451 (holotype nearly complete skeleton)
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